Reset valve



Jne 21, 1955 E. c. EHLKE RESET VALVE Filed Dec. 5, 1951 Fla. 2

United States Patent O RESET VALVE Edward C. Ehlke, Milwaukee, Wis.,assigner to A P Controis Corporation, Milwaukee, Wis., Wisconsin acorporation of This invention relates to a temperature responsive valvewhich opens at a predetermined temperature, remains open until manuallyreset and which cannot be closed until the temperature to which itresponds is below said predetermined temperature.

While not limited to the use described hereinafter, this valve may beused as a safety control in conjunction with a gasoline burning heaterto divert fuel from the burner when the temperature of the heated mediumexceeds a predetermined maximum. This valve is particularly suited foruse with high output heaters of the type employed to supply heated airto aircraft engines (to facilitate engine starting and warm-up in coldclimates) and buildings under construction.

An object of this invention is to provide a simple, dependable valve ofthe type described.

Another object is to provide a valve of the type described which may beopened manually as well as automatically in response to temperature.

A further object is to provide a valve of the type described which mustbe closed manually to place the burner in operation when starting aswell as after the valve has opened. l

Other objects and advantages will be pointed out in, or be apparentfrom, the specication and claims, as will obvious modifications of thesingle embodiment shown in the drawings, in which:

Fig. l is a vertical section through the valve;

Fig. 2 is a fragmentary section taken on line 2 2 in Fig. 1 to shown theoperative connection between the diaphragm and the valve cup; and

Fig. 3 is a schematic diagram showing a use of the present valve.

rl`he schematic layout in Fig. 3 illustrates one use of the presentvalve. Burner nozzle 19 is supplied with gasoline from a pump, notshown, through conduit 12 and the heated medium, in this case air, isblown by means of a fan to the desired location. Valve 14 is placed in tby-pass conduit 16 with its feeler bulb 18 in the heated air so as toopen the valve and by-pass fuel from the nozzle to the sump throughconduit 16 and conduit 20 when the temperature of the heated air exceedsa predetern-lined maximum. After the valve has opened it cannot beclosed until the temperature of the heated medium has decreased belowthe calibration temperature and the valve is manually reset. As will bepointed out more fully hereinafter it is necessary to reset the valveeven though the temperature of the circulating medium is decreased to atemperature as low as 65 F. below zero.

The valve 14 comprises cast body 22 suitably bored to receive threadednipples 24, 26 which respectively receive inlet conduit 16 and outletconduit 20. Spherical valve 28 carried in cup 30 on the upper end ofstem 32 is adapted to seat on valve seat 42 to regulate ow between theinlet and the outlet. Spring 34 biases cup 30 to a position where thecup rests on the upper annular surface of the centrally bored sleeve 36through which stem 32 passes. Sleeve 36 includes a flanged seat v38 atits upper end to serve as a seat for spring 40 which biases the sleeveupwardly to urge valve 28 toward valve 2 seat 42. Cylindrical member 44is threaded on the lower end of sleeve 36 and is provided with aninturned flange 46 against which the headV 48 of pin S0 projecting fromreset pin 52 seats. Reset pin 52 projects through a co-y operating holein member 54 which threadably engages valve body 22 and serves'as a seatfor spring 40. The space around reset pin 52 is suitably sealed by meansof seal 56.

When pin 52 is pulled from the valve body, head 48 engages ange 46 tomove thevalve supporting assembly downwardly to unseat the valve. If thepin is pushed inwardly shoulder 53 will act on the underside of -ange 46to seat the valve subject to the limtations hereinafter pointed out.

It will be noted that flange 38 on sleeve 36 also serves as a seat forpush pins 5S, 58 which straddle the outlet conduit (Fig. 2) and transmitmovement of diaphragm pressure pad 60 to the valve as diaphragm 62ilexes. The holes through which push pins 58 project are of greaterdiameter than the pins and allow the inlet pressure to act on theunderside of diaphragm 62 in the same direction as the force of spring4l) and tends to seat the valve. Spring 64 is compressed betweendiaphragm pad 66 and seat 68 in sealed chamber 7i) to act in oppositionto inlet pressure and spring 40. Pressure in chamber 70 acts ondiaphragm 62 in the same direction as spring 64 and varies as thetemperature of charged feeler bulb 72, connected to the chamber by meansof capillary tube ,'74, varies.

When the valve is closed the pressure under the diaphragm is greatenough to prevent the valve from opening until the temperature of thefeeler bulb exceeds the predetermined temperature. When the temperatureofthe bulb causes the pressure in chamber 70 to overbalance the inletpressure the valve opens to by-pass fuel. When the Valve opens'the inletpressure drops oit markedly, thus decreasing the pressure on theunderside of the diaphragm. The charge in bulb 72 is selected to exert apressure in chamber 70 which is greater than the inlet pressure whenythe valve is open under any expected operating temperature. Therefore,the valve remains fully open and will not close automatically ormodulate when the bulb temperature drops ott. The valve may be seatedmanually by pushing pin 52 to act on flange 46. When the valve is seatedthe inlet pressure will build up su'iciently to hold the Valve closed(assuming, of course, that the bulb ternperature is below thel selectedresponse temperature). With this in mind it will be apparent that thecharge in the feeler bulb must be selected on the basis of the desiredpressure temperature curve for the operating range. `I have employedheptane with satisfactory results over the range from'-65 F. to 350 F.Such a valve must be manually closed to place the burner in operationand when opened manually or automatically it will remain open untilmanually reset. Y

Although but one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be madetherein withoutdeparting from the spirit of the invention or from the scope of theappended "n claims.

, outlet, a diaphragm mounted in said body with the space on one side ofthe diaphragm in communication with the -j inlet pressure, the otherside of the diaphragm being ex- -posed to the pressure in a chamber,charged temperature responsive means operable to exert a variablepressure in said chamber in accordance with temperature variations at aremote location, means operably connecting the da? ligphragm to thevalve to transmit motion from the dia- Patented June 21, 1955 phragm tothe valve, the inletpressure acting on the diaphragm and the valve andexerting a net force in the valve closing direction, the charge in saidtemperature responsive means beingl selected to exert a force on saidother side of said diaphragm lessthan the net force exerted by the inletpressure at all temperatures below a predetermined temperature when thevalve is closed and to exert a force on said other side Vgreater thanthe Vnet force exerted by the inlet pressure when the temperatureexceeds said predetermined temperature to open the valve, the inletpressure being vented to the valve outlet when the valve is open toprevent building up enough inlet pressure to close the valve against theforce on said other side at any temperature, and means for manuallyclosing said valve to allow the inlet pressure to build up sut`rlcientlyto overcome theA pressure on said other side of said diaphragm.

-2. A by-pass valve adapted for use in a fluid system wherein thepressure at the inlet to the valve is greater when the valve is closedthan when the valve is open,

comprising, a body having an inlet and an outlet, a valve and valve seatin said body between the inlet and the outlet for regulating ow from theinlet to the outlet, a diaphragm operably connected to the valve toregulate movements thereof, said diaphragm being mounted in said bodywith one side thereof exposed to inlet pressure and the other sideexposed to a chamber, the inlet pressure acting on the diaphragm and thevalve and exerting a net force in the valve closing direction, chargedtemperature responsive means connected to said chamber for exerting apressure in the chamber which varies with temperature variations at aremote location, the charge in said means being selected to exert aforce on said diaphragm which is greater than said net force at alltemperatures when the valve is open and the inlet pressure is vented tothe outlet and which is less than the net force when the valve is closedexcept when the temperature at said location exceeds a preselectedresponse temperature at which time the pressure on said other side actsto open the valve and vent the inlet pressure to the outlet, and meansfor manually closing said valve and holding the valve closed until thenet force of the inlet pressure builds up suidciently to overcome theforce on said other side of said diaphragm.

3. A by-pass valve comprising a body having an inlet and an outlet, avalve and valve seat in the body between the inlet and the outlet forregulating iiow between the inlet and the outlet, a diaphragm mounted insaid body with one side exposed to inlet pressure and the -other sideexposed to a chamber, means operatively connecting the diaphragm to thevalve to transmit diaphragm movement to the valve, the inlet pressureacting on the diaphragm and the valve and exerting `a net force in thevalve vclosing direction, charged temperature responsive means connectedto said chamber to `exert a pressure in the chamber which varies withtemperature, the force on said other vside of said diaphragm being atall times greater than the net torce on said one side when the valve isopen "to vent the inlet to the outlet, the flow rate through the valvewhen the valve is open being great enough to preclude building up enoughinlet pressure to overcome the force on said other side of saiddiaphragm to close the valve, means for closing the valve and forholding the valve closed While the net force of the inlet pressurebuilds up as a consequence of the closure to overcome the chamberpressure force, the inlet pressure exerting a Vgreater'net forcethan'the force on said other side of said diaphragm `when the valve isclosed and the temperature of said temperature responsive means is lessthan a predetermined maximum, the charge pressure force being greaterthan the net force of the `inlet pressure when the temperature of saidtemperature responsive vmeans is greater than said maximum.

V4. A by-pass valve comprising, a body having an inlet and an outlet, avalve and valve seat in said body between the inlet and the outlet forregulating 'liow ,r

between the inlet and outlet, a diaphragm in said body operativelyconnected to said valve and having one sidel subjected to inletpressure, the inlet pressure acting on the diaphragm and the valve andexerting a net force in the valve closing direction, charged temperaturere sopnsive means acting on the other side of said diaphragm in thevalve opening direction and operative'to open the valve when thetemperature to which it .responds exceeds "a 'predetermined maximum,opening of said valve bein'goperative to vent the inlet to the outletand pass enoughlluid to prevent buildingrup enough netV force `of theinlet pressure to close the valve whereby the force on said other sideof said diaphragm is greater than the net inlet pressure force on saidone side at all response temperatures when the valve is open, and meanstween -the inlet Aandthe outlet for regulating ow from the inlet to theoutlet, a diaphragm mounted in `said body with one side exposed to inletpressure and the other sidelexposed =to pressure in a chamber, meansoperatively connecting the diaphragm to the valve to transmit vdiaphragm4movement to the valve, charged tempera-V ture responsive meansconnected to said chamber to v vary the .pressure in the chamber as theresponse temperature varies, the pressure force in said chamber actingto urgethe valveopen, means for closing said valve fromv the exterior ofthe body to allow the inlet pressure to n buildup :to act onsaiddiaphragm to prevent the chamber pressure from opening the valve at allresponse temperatures below a predetermined maximum, the chamberpressure force acting to overcome theinlet pressure force and open Vthevalve when the response temperature ex,- ceeds said predeterminedmaximum to vent the inlet yto the outlet and prevent the inlet pressurefrom buildingV up to close thevalve unt-il the valve is closed manually.6. A reset valve comprising, a -body having an inlet and an outlet,a'valve and valve-seat in said --body between the inlet and the outletforregulating ow from the inlet 4to the outlet, a spring urging thevalve to its seat, manual'rneans for moving the valve to or fromitsseat, la diaphragm mounted in said body with one side exposed to inletpressure and its other side exposed to pressure in a chamber, a ieelerbulb connected to said chamber and charged to exert varying pressures inthe chamber as the temperature vof the bulb changes, means operativelyconnecting the diaphragm to the valve to transmit diaphragm movement tothe valve, the inlet t pressure .acting on said diaphragm and said valveand exerting a .net force yin the valve closing direction, the chamberpressure force acting on the valve in the valve opening direction, saidcharge having a pressure-temperature characteristic such that thepressure force .on`

said other side of said diaphragm exceeds the net inlet pressureorcewhen the valve is open and the inlet is vented to the outlet toreduce the inlet pressure and prevent building up enough inlet pressureto reclose the valve and is less than t-he net inlet pressure force onysaid one side when said valve is closed except when the temperature ofsaid feeler bulb is greater than a predetermined maxi-mum at which timethe valve opens to vent the vinlet to the outlet.

References Cited in the tile of this patent UNITED STATES PATENTS1,619,130 Jones Mar.V l, 1927 1,988,956 Newell JangZZ, 1935 2,199,498Kaufman May 7, 1940 2,237,261 `McGrath Apr. l, 194iV 2,375,810 NelsonMay 15, 1945 r2,387,792 Holmes Oct. 30, 19,45 2,573,522 Watt Oct. 30,1951

